String Sorcery: Using Chromatics In Music

I've decided to launch a column to supplement the String Sorcery lesson series. Here, I'd like to go into various topics that aren't particularly lessons but are still useful. These could be about different aspects of guitar playing, sharing experiences with certain books, tools, etc., or (in the case of this entry) addressing things that I may have left out of the lessons themselves. Today's topic is the importance of chromatic exercises. A reader kindly pointed out that I didn't explain their importance very much, so I'll do that now:
A sizable portion of people who pick up a guitar utilize chromatic exercises, but many of these individuals stop using them altogether as they advance. Although it is certainly important to learn and practice new things, the basics are always the foundation. To illustrate this, let's say you're building a house. Before you do anything else, you lay the foundation. From there, you can build a strong and sturdy house. Now, let's say that you want to expand your dwelling (perhaps by adding another floor). If you don't upgrade and reinforce the foundation to handle the extra stress, your house may possibly collapse. How does this analogy compare to guitar playing?
Most of the guitarists that I know started out with the same simple chromatic exercises, and it helped them build a decent technical foundation. The simplicity was also the reason for which they abandoned their usage; believing that there was nothing more to gain. From my own experience, I can say that the opposite is true.
Because those common chromatic exercises are so simple (as far as fingerings go), they aid us in maintaining and improving our raw picking speed and base finger dexterity. In general, it makes other things a bit easier to master. Now, I'm not suggesting that you spend months and months on chromatics while practicing nothing else. Instead, I'd suggest that you get a few of them down to a point in which you can play them at a decent speed (like 16th notes at 60 Beats per minute) and then use them as warmups for every practice session. Not only will you be able to warm up, but you'll also be improving at the same time. In "String Sorcery: The Wizard's Tower Pt.2 - Picking And Chromatic Exercises", there are a few that I personally use each day.
Now on to utilizing the chromatic scale in music: It's fairly rare to see people composing music entirely out of the chromatic scale. Nikolai Rimsky-Korsakov and Arnold Schoenberg are two examples of people who did. The rest of us generally utilize the chromatic scale to add a few extra "colors" to a piece of music. There are a few more elaborate ways to do this (such as Schoenberg's 12-Tone System), but most musicians would opt for simple experimentation.
String Sorcery News Update:
The Wizard's Tower portion of the series is very much based on exercises and technical improvement. I'd like for this series to be as all inclusive and informative as possible, so I'm currently working on coming up with lessons in various other categories (particularly in the "For Beginners" section. Also, coming soon in the "Correct Practice" section... String Sorcery: Challenges! This is where I'll pick little things that seem to get ignored and challenge readers to improve on those areas.
Until next time, keep it rockin'!

Keep it up man! I really like your series, I've never actually cared and or followed someones series of posts except this one. Looking forward to the next one!
you make me wanna try doing one of these, I've never contributed to this site other than a handful of dumb questions on the forums

I love chromatics when done tastefully and I try to use em whenever I can! I think the most important thing is to begin on the "correct" (in scale) note and end on another "correct" note. Everything in between should be considered as passing notes.

Um...when dealing with any tonal music, the idea is NOT being "in scale", it's being "in key". Now, "in key" depends mostly on what is being emphasized and the cadences involved. For instance, if I decide to use the key of Emajor, I can easily use notes like bB and still be in key. That's what "chromatic notes" are; they're notes that don't fit the standard notes of the key.
I'm sure you know that Emajor generally consists of the chords Emaj, F#min, G#min, Amaj, Bmaj, C#min, & D#dim. Or it can consist of a simple melody that contains the root notes of those chords. I can supplement chords/melodies with chromatic notes. They can be used as "passing notes", or they can be specially emphasized, in order to make it more obvious to the listener that I'm intentionally creating an interesting harmony.